His official American birth certificate shows he was delivered by a midwife in Brownsville, at the southern tip of Texas. He spent his life wearing American uniforms: three years as a private in the Army, then as a cadet in the Border Patrol and now as a state prison guard.

But when Juan, 40, applied to renew his U.S. passport this year, the government’s response floored him. In a letter, the State Department said it didn’t believe he was an American citizen.

As he would later learn, Juan is one of a growing number of people whose official birth records show they were born in the United States but who are now being denied passports — their citizenship suddenly thrown into question. The Trump administration is accusing hundreds, and possibly thousands, of Hispanics along the border of using fraudulent birth certificates since they were babies, and it is undertaking a widespread crackdown.

In a statement, the State Department said that it “has not changed policy or practice regarding the adjudication of passport applications,” adding that “the U.S.-Mexico border region happens to be an area of the country where there has been a significant incidence of citizenship fraud.”

But cases identified by The Washington Post and interviews with immigration attorneys suggest a dramatic shift in both passport issuance and immigration enforcement.

In some cases, passport applicants with official U.S. birth certificates are being jailed in immigration detention centers and entered into deportation proceedings. In others, they are stuck in Mexico, their passports suddenly revoked when they tried to reenter the United States. As the Trump administration attempts to reduce both legal and illegal immigration, the government’s treatment of passport applicants in South Texas shows how U.S. citizens are increasingly being swept up by immigration enforcement agencies.

Juan said he was infuriated by the government’s response. “I served my country. I fought for my country,” he said, speaking on the condition that his last name not be used so that he wouldn’t be targeted by immigration enforcement.

The government alleges that from the 1950s through the 1990s, some midwives and physicians along the Texas-Mexico border provided U.S. birth certificates to babies who were actually born in Mexico. In a series of federal court cases in the 1990s, several birth attendants admitted to providing fraudulent documents.

Based on those suspicions, the State Department during the George W. Bush and Barack Obama administrations denied passports to people who were delivered by midwives in Texas’s Rio Grande Valley. The use of midwives is a long-standing tradition in the region, in part because of the cost of hospital care. [MORE]